Thinking inside the box: Solar Charged Jump Starter?

[XERTYX]

So for some projects I've mentioned I have a need for a 12v air compressor. Also I am not running solar at the moment and no longer have my old batteries or panels.

My sister has a 12 volt jump box she has to use on a lot of cold mornings that recharges thru 120V. It has an air compressor, 12 Volt jumpstarter, cigarette lighter socket, USB I believe, lantern, and a volt meter. Some models have a built in inverter as well for 120V AC.

During the summer months I often sit around the fire at night listening to music, slow cooking, maybe having an adult beverage and I find the need for power. But not lots.

Ok so I'll buy one and start my experiments. Then again... how will I recharge it if shore power isnt available? Do I want to break the case open on day one of ownership to install an MPPT controller on the battery and rig an MC4 connector in place on the outside? Dear me. Lightbulb!?

Why not recharge thru AC? It has a built in charger that has the proper charging algorithm for the battery chemistry. I'll be maintaining its charge from AC when I do my solar build anyway. And I have no idea what chemistry the battery uses anyway. They used to be SLA batteries I think but these new models are super lightweight so I'm thinking they could have lithium batteries.

So build the solar bank now and add the jumpstarter later? Or figure out a way to recharge it as is?

Here's the idea. I'm planning on buying a 100 watt poly panel anyway then buy 2 more as budget allows. What if I wired the panel straight in to an inverter rated at say 75 watts? Panels put out 18 volts or more if I remember correctly so the inverter would need to regulate voltage or I'd have to use a voltage limiting circuit between the 2. It sounds a bizarre setup even to me and I'm the looney who hatched the scheme in the first place. 

Possible outcomes. I fry my inverter. I fry the jumper Circuitry. I fry the internal battery in the jumper. If I break It i get to take it apart and look for the gremlins that make it tick so win win. Right?

 

[Gr8ful]

Why nut just use an invertor to run a small compressor. I use a Makita Hot Dog.

 

[bullfrog]

I during this past winter used 2 jumper packs (on sale at Harbor Freight for $40 each) to charge my Ryobi 18 volt batteries using a Ryobi vehicle charging station. This kept me from having to fire up the generator as often or late at night while working on projects. Usually the next morning I would run the generator two hours to four hours to do a bulk charge on my house batteries after which on good days the solar would finish topping everything up. While running the generator I would also charge the jump packs with the 120 AC charging cord. Worked pretty well and as I had two vehicles I always had a charged up jump pack for road trips. It helped keep my house batteries from getting overly discharged as well.

 

[jonyjoe303]

The inverter need to be connected to a battery first for stable power. If connected to panel, you would get unstable power. The best way to charge it is with the 100 watt panel and a cheap pwm controller, there is no way to overcharge the jumpack, 100 watts will produce about 5 amps which is alot better then what the AC wallwart can produce.

All my jumpacks I open them up and add xt60 connectors directly to the battery, that way I can charge directly from any dc source, I can even connect it to a more powerful AC wallwart. The wallwarts that come with jumpacks are too weak (charge at 1 amp) to fast charge a lead acid. The jumpack batteries usually 18ah agm can handle being charged at high amps, I have connected them to my 240 watt panel/ 20 amp mppt and charged it that way. Even with my 240 watt panel it charged at about 6 amps, nothing a agm couldn't handle.

 

[Seminole Wind]

if the jump pack you mention is a 12 volt lead acid battery then it shouldnt be too hard to crack it open and hook up a charge controller from you solar panel and you could even use that battery to buffer a small inverter. it may be too much hassle to try and hack an inverter to run directly off the solar panel source. it can be done but is beyond my electronics skilz

 

[XERTYX]

The inverter need to be connected to a battery first for stable power. If connected to panel, you would get unstable power. The best way to charge it is with the 100 watt panel and a cheap pwm controller, there is no way to overcharge the jumpack, 100 watts will produce about 5 amps which is alot better then what the AC wallwart can produce.

All my jumpacks I open them up and add xt60 connectors directly to the battery, that way I can charge directly from any dc source, I can even connect it to a more powerful AC wallwart. The wallwarts that come with jumpacks are too weak (charge at 1 amp) to fast charge a lead acid. The jumpack batteries usually 18ah agm can handle being charged at high amps, I have connected them to my 240 watt panel/ 20 amp mppt and charged it that way. Even with my 240 watt panel it charged at about 6 amps, nothing a agm couldn't handle.

I have thought of this actually. I think I'd need a high farad electrolytic capacitor wired in parallel with the panel before the inverter to keep the voltage stable. What are your thoughts?

You may have noticed I have the mindset of just because one way is the best way are there advantages to doing the exact opposite? I lead by bad example. Haha.

 

[rosiemartinez1211]

I'm SO glad you asked this question. I by no means understand how solar works, but I do know I need a panel, a controller, a battery and an inverter. I have a CAT jump starter, air compressor, AC, 4 usb power pack. This is an inverter, correct?

I haven't bought my solar setup yet simply cuz I don't know which way to go. I too kept wondering if I could charge it from my solar connection. But how would I charge it? I don't know how to take it apart. Can I connect it to the controller, if so how? Can I connect straight to the battery? Or do I still need the inverter? But then technically I have one inverter charging another inverter, right? And why would that make sense.

So I stay paralyzed in pulling the trigger on what to buy.

 

[Seminole Wind]

if your cat jump pack has plugs like a wall plug in a home. it would have an inverter in it. but you would have to find the specs printed on it or in a manual to see how much power it would provide.

trying to "hack" something like a jump pack is not something i recommend till you understand all the parts and pieces. it is not a hard thing to do to open up a 12 volt lead acid based jump pack and wire in a charge controller to hook up a solar panel. but you need to understand how it all works first. if you do have an inverter in there, remember that makes the same kind of electricity you have in houses. it can kill you

if you want to get into hacking electrical things it would be very wise to really study up. start with small low voltage projects and work up. a couple good books on basic electrical an electronics and lots of reading on the internet can bring you up to speed pretty quick.

if that is not something you want to invest time it it would be wise to buy stuff already made to do want you need.

 

[MrAlvinDude]

I think I'd need a high farad electrolytic capacitor wired in parallel with the panel before the inverter to keep the voltage stable. What are your thoughts?

Any 12V energy storage device will likely work, for providing a stable voltage source for the input to an inverter.

I only have very limited experience with super capacitors (I have a six-pack of 2600F 2.5V capacitors). But I only played around with them once, for a few hours, a long time ago, so I would not really know what would be the got'ya(s) on that issue, but I would imagine that they are quite over-voltage sensitive, once they reach full capacity.

A pack like that can however make some rather spectacular spark "fireworks" - that is for sure.
This guy has made a video, using some of those super capacitors.


You asked for thoughts, those are my thoughts.

 

[XERTYX]

That's an awesome video. That reminds me of some of the projects I did as a kid with capacitors. The flash circuit in a disposable camera has a pretty beefy capacitor in it. I knew I needed to discharge it before I removed it from the circuit board and I used a screwdriver to short circuit it. BANG FLASH and the tip of my screwdriver was gone. Haha. 

Capacitors are very dangerous as they store an electrical charge high enough to kill a person for years after it was last plugged in. You should NEVER EVER remove a capacitor from a microwave oven even if you know what you're doing. A microwave capacitor is probably what I'd use if I decide to build out my ridiculous project.

 

[XERTYX]

I'm SO glad you asked this question. I by no means understand how solar works, but I do know I need a panel, a controller, a battery and an inverter. I have a CAT jump starter, air compressor, AC, 4 usb power pack. This is an inverter, correct?

I haven't bought my solar setup yet simply cuz I don't know which way to go.  I too kept wondering if I could charge it from my solar connection. But how would I charge it? I don't know how to take it apart.  Can I connect it to the controller, if so how?  Can I connect straight to the battery? Or do I still need the inverter? But then technically I have one inverter charging another inverter, right?  And why would that make sense.

So I stay paralyzed in pulling the trigger on what to buy.

If your pack has AC then yes it has an inverter. The inverter is what converts the battery DC voltage into AC voltage like you have in the house. As Seminole wind said you'll need to check the manual and see how many watts the inverter provides to determine if that's going to be enough for you. For my purposes I'll only recharge a cell phone and maybe run LED lights around camp for a few hours at night. I wouldnt need much. But if you want to run a television/DVD combo for instance the jumper pack will likely not be a viable option. You CAN remove the casing and wire in a charge controller but it is a big task if you're not familiar with taking stuff apart. 

I wanted to charge mine WITHOUT opening it. Just for the sake of argument mainly. I'd suggest building your own bank and array if it's going to be your house battery. If you would only use it on weekends when you drive to the country and camp then it might suit your needs for lighting and charging a cell or tablet. It all depends on your needs. 

If you wanna post what you plan to do with your personal power plant I'll put in my 2 cents. I'm sure others will as well.

 

[Seminole Wind]

Any 12V energy storage device will likely work, for providing a stable voltage source for the input to an inverter.

I only have very limited experience with super capacitors (I have a six-pack of 2600F 2.5V capacitors). But I only played around with them once, for a few hours, a long time ago, so I would not really know what would be the got'ya(s) on that issue, but I would imagine that they are quite over-voltage sensitive, once they reach full capacity.

A pack like that can however make some rather spectacular spark "fireworks" - that is for sure.
This guy has made a video, using some of those super capacitors.


You asked for thoughts, those are my thoughts.

if anyone wants to see how to run an inverter straight off an electrical source, you might want to crack open a honda inverter generator. not the same but similar. also there are, or at least used to be larger solar panels that came with an ac inverter built right in. these were intended to be grid-tie set ups so they had safety features that prevented power output unless they saw line power but they were clearly ac producing inverters run directly from a solar panel. and all your grid-tie inverters convert the solar panel output directly to ac line power with no battery storage option. dig deep into those systems and i bet there is a way. but i doubt there is a simple redneck solution to befound on a van dwellers forum. at least not till the OP figures it out and comes back to share... ;-)